Certain known data transfer systems use data lines for the transfer of both data and addressing information between a source and a plurality of receiving modules. These systems require that all receiving modules operate momentarily in a common address-receiving condition to assure that subsequently-appearing data signals may be applied to the proper receiving modules. The timing restrictions thus imposed generally limit the data transfer operation to a sequence of events, each of which must be performed within specified time periods and usually restricts the data transfer to only one receiving module at a time.